ORGANOIDS FOR CYSTIC FIBROSIS AND THE LIVING CANCER
Human organoids are a vital source for precision medicine. They can be useful to select an appropriate drug for the patients with genetic diseases or cancer. Cystic fibrosis is a relatively common genetic disease with approximately 90,000 patients suffering with it worldwide. Although loss of function of the CFTR gene, which encodes a chloride channel regulating the mucosal environment, is the main cause, with nearly 2000 mutations have been reported that affects the function or expression of CFTR, thus making it a genetically heterogeneous disease (1).
Organoid assays used in drug response screen
Two drugs namely VX-770 a CFTR potentiator that improves chloride channel activity and other VX-809 a CFTR corrector that helps mutant protein folding which are readily available for patients with CF who carry specific mutations. Rectal organoids isolated from small biopsies have been used in forskolin-induced swelling assays to assess the signaling pathways; it is also studied that the assay can faithfully predict patient response to individual drugs as well as to combined treatments. Also, with this in-vitro assays it is possible to identify which patients’ rare mutation would respond to and could be treated with existing therapies (1).
Cancer organoids: tumouroids
Human organoids play a prominent role in enhancing our understanding of human cancers. Human cell lines, mouse cancer models have been the main experimental platform for studies of human cancer, however the advent of organoid technology, transformed cancer tissues have been grown in-vitro as cancer organoids also known as tumouroids or canceroids, demonstrating that this technology is applicable to diseased tissues as well as to normal epithelia.
An analysis of drug responses in patients and in their matched cancer organoids led to the conclusion that responses to the drugs are highly similar to a drug with no anti-tumor activity in organoids did not demonstrate efficacy in the matched patients, and drugs that showed an effect in the organoid cultures were matched by patient response in close to 90% of cases. The sample size and cancer types analyzed remains limited, thus more rigorous investigation will be needed before cancer organoids so that they can be routinely adopted in vitro patient. (2,3,4)
1. Rusnati, M. et al. Recent strategic advances in CFTR drug discovery: an overview. Int. J. Mol. Sci. 21, 2407 (2020).
2. Dekkers, J. F. et al. Characterizing responses to CFTR-modulating drugs using rectal organoids derived from subjects with cystic fibrosis. Sci. Transl. Med. 8, 344ra384 (2016).
3. Berkers, G. et al. Rectal organoids enable personalized treatment of cystic fibrosis. Cell Rep. 26, 1701–1708 (2019).
4. Vlachogiannis, G. et al. Patient-derived organoids model treatment response of metastatic gastrointestinal cancers. Science 359, 920–926 (2018).